The invention relates to sulphamoylbenzoic acids of the formula ##STR1## in which R.sub.1 is a substituted or unsubstituted aryl radical, X is oxygen or sulphur, R.sub.2 is hydrogen, lower alkyl or oxa-lower alkyl or an aryl radical, Py is a substituted or unsubstituted 1-pyrrolyl radical and n is an integer from 0 to 4, and salts of these compounds. They are valuable diuretics and saliuretics.